OOPS & Python Programming (4351108) - Winter 2024 Solution

Question 1(a) [3 marks]

List out features of python programming language.

Answer:

Mnemonic: "Simple Free Cross Interpreted Object Large"

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Question 1(b) [4 marks]

Write applications of python programming language.

Answer:

Mnemonic: "Web Data Machine Desktop Game Auto"

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Question 1(c) [7 marks]

Explain various datatypes in python.

Answer:

Code Example:

Python

Mnemonic: "Integer Float String Boolean List Tuple Dict Set"

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Question 1(c OR) [7 marks]

Explain arithmetic, assignment, and identity operators with example.

Answer:

Arithmetic Operators:

Assignment Operators:

Identity Operators:

Code Example:

Python

Mnemonic: "Add Assign Identity"

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Question 2(a) [3 marks]

Which of the following identifier names are invalid? (i) Total Marks (ii)Total_Marks (iii)total-Marks (iv) Hundred$ (v) _Percentage (vi) True

Answer:

Invalid identifiers: Total Marks, total-Marks, Hundred$, True

Mnemonic: "Space Hyphen Dollar Keyword = Invalid"

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Question 2(b) [4 marks]

Write a program to find a maximum number among the given three numbers.

Answer:

Python

Alternative using max() function:

Python

Mnemonic: "Input Compare Display"

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Question 2(c) [7 marks]

Explain dictionaries in Python. Write statements to add, modify, and delete elements in a dictionary.

Answer:

Dictionary is a collection of key-value pairs that is ordered, changeable, and does not allow duplicate keys.

Operations Table:

Code Example:

Python

Dictionary Properties:

• Ordered: Maintains insertion order (Python 3.7+)
• Changeable: Can modify after creation
• No Duplicates: Keys must be unique

Mnemonic: "Key-Value Ordered Changeable Unique"

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Question 2(a OR) [3 marks]

Write a program to display the following pattern.

Answer:

Python

Output:

1
1 2
1 2 3
1 2 3 4
1 2 3 4 5

Mnemonic: "Outer Row Inner Column Print"

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Question 2(b OR) [4 marks]

Write a program to find the sum of digits of an integer number, input by the user.

Answer:

Python

Alternative Method:

Python

Mnemonic: "Input Extract Sum Display"

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Question 2(c OR) [7 marks]

Explain slicing and concatenation operation on list.

Answer:

List Slicing: Extracting portion of list using [start:stop:step] syntax.

Slicing Syntax Table:

Concatenation: Joining two or more lists using + operator or extend() method.

Code Example:

Python

Key Points:

• Slicing: Creates new list without modifying original
• Concatenation: Combines lists into single list
• Negative indexing: list[-1] gives last element

Mnemonic: "Slice Extract Concat Join"

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Question 3(a) [3 marks]

Define a list in Python. Write name of the function used to add an element to the end of a list.

Answer:

List Definition: A list is an ordered collection of items that is changeable and allows duplicate values.

Properties Table:

Function to add element: append()

Example:

Python

Mnemonic: "List Append End"

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Question 3(b) [4 marks]

Define a tuple in Python. Write statement to access last element of a tuple.

Answer:

Tuple Definition: A tuple is an ordered collection of items that is unchangeable and allows duplicate values.

Properties Table:

Accessing Last Element:

Python

Mnemonic: "Tuple Unchangeable Negative Index"

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Question 3(c) [7 marks]

Write statements for following set operations: create empty set, add an element to a set, remove an element from set, Union of two sets, Intersection of two sets, Difference between two sets and symmetric difference between two sets.

Answer:

Set Operations Table:

Code Example:

Python

Mnemonic: "Create Add Remove Union Intersect Differ Symmetric"

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Question 3(a OR) [3 marks]

Define a string in Python. Using example illustrate (i) How to create a string. (ii) Accessing individual characters using indexing.

Answer:

String Definition: A string is a sequence of characters enclosed in quotes (single or double).

(i) Creating String:

Python

(ii) Accessing Characters:

Python

Mnemonic: "String Quotes Index Access"

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Question 3(b OR) [4 marks]

Explain list traversing using for loop and while loop.

Answer:

List Traversing means visiting each element of list one by one.

For Loop Traversing:

Python

While Loop Traversing:

Python

Comparison Table:

Mnemonic: "For Simple While Control"

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Question 3(c OR) [7 marks]

Write a program to create a dictionary with the roll number, name, and marks of n students and display the names of students who have scored marks above 75.

Answer:

Python

Sample Output:

Enter number of students: 2

Enter details for student 1:
Roll number: 101
Name: John
Marks: 80

Enter details for student 2:
Roll number: 102
Name: Alice
Marks: 70

Students with marks above 75:
------------------------------
Name: John, Marks: 80.0

Total high performers: 1

Mnemonic: "Input Store Filter Display"

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Question 4(a) [3 marks]

Write any three functions available in random module. Write syntax and example of each function.

Answer:

Random Module Functions:

Code Example:

Python

Mnemonic: "Random Randint Choice"

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Question 4(b) [4 marks]

Write the advantages of functions.

Answer:

Function Advantages:

Example:

Python

Mnemonic: "Reuse Modular Debug Read Maintain Avoid"

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Question 4(c) [7 marks]

Write a program that asks the user for a string and prints out the location of each 'a' in the string.

Answer:

Python

Sample Output:

Enter a string: Python Programming

Character 'a' found at positions: [12]
Detailed locations:
Position 12: 'a'

Alternative approach:
'a' found at position 12

Enhanced Version:

Python

Mnemonic: "Input Loop Check Store Display"

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Question 4(a OR) [3 marks]

Explain local and global variables.

Answer:

Variable Scope Types:

Code Example:

Python

Global Keyword:

Python

Mnemonic: "Local Inside Global Everywhere"

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Question 4(b OR) [4 marks]

Explain creation and use of user defined function with example.

Answer:

Function Creation Syntax:

Python

Function Components:

Example:

Python

Mnemonic: "Define Call Return Parameter"

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Question 4(c OR) [7 marks]

Write a program to create a user defined function calcFact() to calculate and display the factorial of a number passed as an argument.

Answer:

Python

Recursive Version:

Python

Sample Output:

Enter a number: 5
Factorial of 5 is: 120

Testing with different values:
calcFact(0) = 1
calcFact(1) = 1
calcFact(5) = 120
calcFact(10) = 3628800
calcFact(-3) = Factorial is not defined for negative numbers

Mnemonic: "Define Check Loop Multiply Return"

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Question 5(a) [3 marks]

Give difference between class and object.

Answer:

Class vs Object Comparison:

Code Example:

Python

Mnemonic: "Class Blueprint Object Instance"

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Question 5(b) [4 marks]

State the purpose of a constructor in a class.

Answer:

Constructor Purpose:

Types of Constructors:

Example:

Python

Mnemonic: "Initialize Automatic Memory Default"

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Question 5(c) [7 marks]

Write a program to create a class "Student" with attributes such as name, roll number, and marks. Implement method to display student information. Create object of the student class and show how to use method.

Answer:

Python

Sample Output:

Creating Student Objects:

=== Student 1 Details ===
------------------------------
STUDENT INFORMATION
------------------------------
Name: John Doe
Roll Number: 101
Marks: 85
------------------------------
Grade: A

=== Student 2 Details ===
------------------------------
STUDENT INFORMATION
------------------------------
Name: Alice Smith
Roll Number: 102
Marks: 92
------------------------------
Grade: A+

Class Components:

• Attributes: name, roll_number, marks
• Constructor: __init__() method
• Methods: display_info(), calculate_grade(), display_grade()
• Objects: student1, student2, student3

Mnemonic: "Class Attributes Constructor Methods Objects"

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Question 5(a OR) [3 marks]

State the purpose of encapsulation.

Answer:

Encapsulation Purpose:

Implementation Example:

Python

Benefits:

• Security: Data cannot be accessed directly
• Maintenance: Easy to modify internal implementation
• Validation: Can add validation in getter/setter methods

Mnemonic: "Hide Protect Control Secure Modular"

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Question 5(b OR) [4 marks]

Explain multilevel inheritance.

Answer:

Multilevel Inheritance is when a class inherits from another class, which in turn inherits from another class, forming a chain.

Structure Diagram:

goat

Characteristics Table:

Code Example:

Python

Mnemonic: "Chain Inherit Level Access"

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Question 5(c OR) [7 marks]

Write a Python program to demonstrate working of hybrid inheritance.

Answer:

Hybrid Inheritance combines multiple types of inheritance (single, multiple, multilevel) in one program.

Structure Diagram:

goat

Code Example:

Python

Sample Output:

=== Hybrid Inheritance Demo ===

1. Creating regular dog:
Animal Buddy created
Buddy the Retriever is barking
Buddy is guarding the house

2. Creating regular bird:
Animal Eagle created
Eagle is flying with 200cm wings
Eagle lays eggs

3. Creating magical flying dog:
Animal Superdog created
Animal Superdog created
Magical Superdog created with both mammal and bird features!

Superdog's Abilities:
-------------------------
Superdog is eating
Superdog is sleeping
Superdog gives birth to live babies
Superdog the Husky is barking
Superdog is guarding the house
Superdog is flying with 150cm wings
Superdog lays eggs
Superdog is flying and barking at the same time!

Inheritance Types in This Example:

1. Single: Mammal ← Animal, Bird ← Animal, Dog ← Mammal
2. Multiple: FlyingDog ← Dog + Bird
3. Multilevel: FlyingDog ← Dog ← Mammal ← Animal
4. Hybrid: Combination of all above

Key Features:

• Multiple Parent Classes: FlyingDog inherits from both Dog and Bird
• Method Resolution Order: Python follows MRO to resolve method conflicts
• Super() Usage: Proper initialization of parent classes
• Combined Functionality: Access to methods from all parent classes

Mnemonic: "Hybrid Multiple Single Multilevel Combined"